Effect of high‐flow nasal oxygen on postoperative oxygenation in obese patients: A randomized controlled trial

Effect of noninvasive respiratory support after extubation on postoperative pulmonary complications in obese patients: A systematic review and network meta-analysis

STUDY OBJECTIVE

Obesity is associated with an increased risk of sleep-disordered breathing (SDB) and postoperative pulmonary complications (PPCs). Postoperative noninvasive respiratory support (NRS) has been recommended to obese patients despite the controversy about its benefit. The network meta-analysis (NMA) was used in this study to compare the effect of different methods of NRS on preventing PPCs in obese patients.

DESIGN

This study is a network meta-analysis.

SETTING

Post-anesthesia care unit and inpatient ward.

PATIENTS

20 randomized controlled trials involving 1184 obese patients were included in the final analysis.

INTERVENTIONS

One of the four NRS techniques, which include continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP), high-flow nasal cannula (HFNC), or conventional oxygen therapy (COT), was performed after general anesthesia.

MEASUREMENTS

The primary outcome was the incidence of PPCs, e.g., atelectasis, pneumonia, hypoxemia, and respiratory failure. The secondary outcomes included the incidence of oxygen treatment failure and anastomotic leakage, oxygenation index, and length of hospital stay (LOS). RevMan 5.3 and STATA 16.0 were used to analyze the results and any potential bias.

MAIN RESULTS

Compared with COT, BiPAP and HFNC were both effective in reducing the occurrence of postoperative atelectasis. There were no significant differences in the occurrence of other PPCs including pneumonia, hypoxemia and respiratory failure between the four NRS techniques. CPAP and HFNC were superior to other techniques in improving oxygenation and shortening LOS respectively. No differences were found in oxygen treatment failure and anastomotic leakage between the patients with different NRS. HFNC ranked the first in five of the eight outcomes (hypoxemia, respiratory failure, treatment failure, anastomotic leakage, LOS) in this review by the surface under the cumulative ranking curve (SUCRA).

CONCLUSION

Among the four postoperative NRS techniques, HFNC seems to be the optimal choice for obese patients which shows certain advantages in reducing the risk of PPCs and shortening LOS.

A Narrative Review of the Clinical Trials in Sleep-Related Breathing Disorders from 2022 to Present

Sleep-related breathing disorders (SRBD) comprise obstructive sleep apnea (OSA), central sleep apnea (CSA), obesity-hypoventilation syndrome (OHS), as well as isolated sleep-related hypoxemia (ISRH), according to the recent International Classification of Sleep Disorders 3. During the last decades, there have been cumulative research reports indicating an association between the SRBD and increased cardiometabolic illness and death, as well as decreased quality of life. Notwithstanding, the results have been inconclusive, and the evidence level was not high regarding the effect of treatment for the SRBD on adverse outcomes. In the current work, we aim to give a comprehensive review of the clinical trials published from January 2022 to August 31, 2023. We highlight the heterogeneity of cardiometabolic disorders among adults with SRBD and particularly emphasize OSA management, drug therapy for OSA, positive airway pressure (PAP) therapy and cardiovascular outcomes, other effects of PAP in pregnancy and neurocognitive function, as well as the effects of surgical treatment and oral appliances. We also underline future directions in OSA management, telemonitoring, and druginduced sleep endoscopy in managing the SRBD, especially OSA. We ascertain that more studies are needed within the CSA, OHS, and ISRH research fields.

Practice Changing Updates in Perioperative Medicine Literature 2022. A Systematic Review

Perioperative medicine is a rapidly growing multidisciplinary field with significant advances published each year. In this review, we highlight important perioperative publications in 2022. A multi-database literature search from January to December of 2022 was undertaken. Original research articles, systematic reviews, meta-analyses, and guidelines were included. Abstracts, case reports, letters, protocols, pediatric and obstetric articles, and cardiac surgery literature were excluded. Two authors reviewed each reference using the Distiller SR systematic review software (Evidence Partners Inc., Ottawa, Ont, Canada). A modified Delphi technique was used to identify 8 practice-changing articles. We identified another 10 articles for tabular summaries. We highlight why these articles have the potential to change clinical perioperative practice and areas where more information is needed.

Efficacy of High-Flow Nasal Cannula versus Conventional Oxygen Therapy in Obese Patients during the Perioperative Period: A Systematic Review and Meta-Analysis

Background. Obesity is a risk factor for severe airway obstruction and hypoxemia. High-flow nasal cannula (HFNC) is considered as a novel method for oxygen therapy, but the efficacy of HFNC for obese patients is controversial. This meta-analysis aimed to assess the efficacy of HFNC compared with conventional oxygen therapy (COT) in obese patients during the perioperative period. Methods. We searched the PubMed, Embase, Web of Science, the Cochrane Library, and Google scholar databases for randomized controlled trials (RCTs) that compared the efficacy of HFNC with COT in obese patients during the perioperative period. The primary outcome was the incidence of hypoxemia, while the secondary outcomes included the lowest SpO2, the need for additional respiratory support, and the hospital length of stay (LOS). Results. Twelve trials with 798 obese patients during the perioperative period were included. Compared with COT, HFNC reduced the incidence of hypoxemia (RR, 0.60; 95% CI, 0.43 to 0.83; $P=0.002$ ; I2 = 24%; 8 RCTs; n = 458), increased the lowest SpO2 (MD, 2.88; 95% CI, 1.53 to 4.22; $P<0.0001$ ; I2 = 32%; 5 RCTs; n = 264), decreased the need for additional respiratory support (RR, 0.43; 95% CI, 0.21 to 0.88; $P=0.02$ ; I2 = 0%; 3 RCTs; n = 305), and shortened the hospital LOS (MD, −0.31; 95% CI, −0.57 to −0.04; $P=0.02$ ; I2 = 0%; 3 RCTs; n = 214). Conclusions. This meta-analysis showed that compared with COT, the use of HFNC was able to reduce the incidence of hypoxemia, increase the lowest SpO2, decrease the need for additional respiratory support, and shorten the hospital LOS in obese patients during the perioperative period. Well-organized trials with large sample size should be conducted to support our findings.